1. Field of the Invention
The present invention relates to a technical field of display, more particularly, relates to an electroluminescent device and a method for producing the electroluminescent device.
2. Description of the Related Art
An organic light emitting diode (OLED) display panel has many excellent advantages, such as, self-luminescence without a back light source, high contrast ratio, small thickness, wide angle of view, quick response, flexibility, adaptability to a wide range of temperatures, simple configuration and manufacturing process, etc. Thereby, the OLED display panel is regarded as a next generation of flat panel display in new technology.
However, since about 30% of photons are limited by a total reflection of a glass substrate and about 50% of photons are limited by a transverse guided wave of an organic layer, only about 20% of photons can exit out of the OLED device. The external quantum efficiency of the OLED device at most reaches 17%. The low external quantum efficiency and light extraction efficiency cause the OLED device to have a low light efficiency, a large power consumption, a high chip heat, a short life, etc.